Device and a method for metal plating

Abstract

A device and a method for metallic electrolytic coating of an object of electrically conductive material, wherein the object has at least two surface portions that are desired to be coated with layers of different thicknesses. The device includes an anode. The device is designed to receive the object in such a way that the object constitutes a cathode and that, upon receipt of the object, a space is formed for receiving a liquid-absorbing material and an electrolyte for coating the object. The body of the anode includes at least two surface portions) that have different electrical conductivity and that are arranged opposite to the surface portions of the received object.

1. A device for metallic electrolytic coating of an object of electrically conductive material, wherein the object has at least two surface portions that are desired to be coated with layers of different thicknesses, the device comprising:
 a rotationally symmetrical anode comprising a body, wherein the device is designed to receive the object in such a way that the object constitutes a cathode and the anode comprises at least two surface portions that have different electrical conductivity and that are arranged opposite to said surface portions of the received object, and upon receipt of the object by the device, a space is formed between the anode and the object for receiving an electrolyte for coating the object, wherein said space is arranged for receiving an electrolyte comprising a silver salt solution and comprises a liquid-absorbing material, wherein said anode comprises at least two channels extending therethrough for the supply of electrolyte out on the surface of said anode, whereby one channel opens out at one of said surface portions of the anode and another channel opens out at the other one of said surface portions of the anode, and wherein one of said channels has a cross-section area that is smaller than a cross-section area of another of said channels. 
 
     
     
       2. The device according to  claim 1 , wherein one of said surface portions of the anode has a conductivity that is near zero, and another one of said surface portions of the anode has a conductivity that is significantly greater than zero. 
     
     
       3. The device according to  claim 1 , wherein one of said surface portions of the anode has a first conductivity that is significantly greater than zero and another one of said surface portions of the anode has a second conductivity that is significantly greater than zero, the first conductivity being different from the second conductivity. 
     
     
       4. The device according to  claim 1 , wherein said anode and the object are adapted to rotate relative to each other. 
     
     
       5. The device according to  claim 1 , further comprising:
 a degreaser configured to degrease the object to be coated. 
 
     
     
       6. The device according to  claim 5 , wherein said channels are adapted to distribute degreasing liquid out into said space. 
     
     
       7. The device according to  claim 1 , further comprising:
 a pickler configured to carrying out pickling of the object. 
 
     
     
       8. The device according to  claim 7 , wherein said channels are adapted to distribute pickling liquid out into said space. 
     
     
       9. The device according to  claim 1 , wherein the object is rotationally symmetrical. 
     
     
       10. A method for metallic electrolytic coating of an object of electrically conductive material, wherein the object has at least two surface portions that are desired to be coated with layers of different thicknesses with at least one device comprising a rotationally symmetrical anode that has a body, wherein the device is designed to receive the object and the object constitutes a cathode, wherein said anode has an essentially constant diameter over the length opposite to said object, the method comprising:
 receiving the object with the device, whereby a space is formed between said anode and the received object, 
 placing said surface portions of the object opposite to at least two surface portions of the anode which have different electrical conductivity, 
 adding liquid-absorbing material to said space, 
 supplying an electrolyte comprising a silver salt solution to the space electrifying at least one of said surface portions of said anode, whereby coating to different layer thicknesses of said surface portions on the object is carried out, 
 supplying electrolyte to the surface of said anode through at least two channels extending through the anode, whereby one channel opens out at one of said surface portions of said anode and the other channel opens out at the other one of said surface portions of said anode, and wherein a volume of flow per unit of time is smaller in one of said channels compared with another one of said channels. 
 
     
     
       11. The method according to  claim 10 , wherein said surface portions of said anode comprise a first surface portion that has a conductivity that is near zero, and a second surface portion has a conductivity that is significantly greater than zero, the second surface portion then being electrified. 
     
     
       12. The method according to  claim 10 , wherein said surface portions of said anode comprise a first and a second surface portion which have a conductivity that is significantly greater than zero, whereby both surface portions are electrified. 
     
     
       13. The method according to  claim 12 , wherein said first surface portion of said anode has a first conductivity and said second surface portion of said anode has a second conductivity, whereby the first conductivity differs from the second conductivity. 
     
     
       14. The method according to  claim 13 , wherein the method comprises electrifying said surface portions simultaneously, whereby simultaneous coating to different layer thicknesses of said surface portions on the object is carried out. 
     
     
       15. The method according to  claim 10 , further comprising:
 rotating said anode and said object relative to each other. 
 
     
     
       16. The method according to  claim 10 , where the object is rotationally symmetrical.